A new technique more accurately measures the masses of supermassive black holes, providing astronomers with fresh data to explore the interactions between these monsters and their host galaxies.

Astrophysicist Timothy Davis of the European Southern Observatory and colleagues tracked the motion of cold carbon monoxide gas orbiting a black hole in the center of the galaxy NGC 4526. To do so, they used the Combined Array for Research in Millimeter-wave Astronomy telescope, a network of 23 mic...